One of the Cemestos prefab homes built to secretly house thousands of Manhattan Project workers.

Though its celestial ceiling is impressive, the true star is the vast collection of French books.

This mosaic dedicated to John Lennon was tended for years by a Beatles super-fan.

During the holidays, a vintage subway train whisks New Yorkers back in time.

A secretive collection featuring objects that were designed specifically for U.S. intelligence operations.

A miniature city within a city, complete with traffic signs, signals, and streets to teach Baltimore's youth traffic safety laws.

Once part of a dam servicing an early 19th century grist mill, the tucked-way falls are a tricky-to-find urban oasis.

This bridge is haunted by the ghost of a distraught mother.

The city is full of whimsical portals to another world.